Active Audio Calling Device Identification System

ABSTRACT

A system for identifying the calling device used to place a call in to an enterprise call center. The system also provides information about the network path through which the call was delivered. The system uses active “pinging” in the audio channel during the first few seconds of the call. The device of the invention sends a special sequence of audio tones from the callee to the caller over the audio channel. The system then records and analyses the resulting incoming audio and compares them with the original tones. The system uses that information to characterize the calling device, and possibly the network path as well. The system checks this information against previously stored information from a known valid caller to aid in verifying the identity of the caller, or to flag the call for further assessment via other methods.

CLAIM OF PRIORITY TO PRIOR APPLICATION

This application claims the benefit of the filing date of U.S.Provisional Application Ser. No. 62/686,951, filed on Jun. 19, 2018, theentire disclosure of which is hereby incorporated by reference in itsentirety into the present disclosure.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention primarily relates to systems and methods foridentifying and authenticating the calling device used to place a call,particularly to calls to an enterprise call center. The disclosedsystems and methods may also provide information about the network paththrough which the call was delivered. This is important for bothsecurity and efficiency in handling incoming calls.

2. Description of Related Art

Many enterprises, such as banks, have a need to validate andauthenticate the identity of a caller who is placing a telephone call into their system. This is important for both security reasons and forimproving the efficiency in handling and routing calls. Companies havebeen looking for reliable and efficient systems to route users with ahigh likelihood of being fraudulent to specially trained operatives,increasing the efficiency of their call centers while simultaneouslydecreasing the amount of fraud.

Traditionally, there are four categories of authentication methods, eachcarrying its own properties, exploits, and problems. The categories areknowledge-based (for example, what the user knows like a PIN number),token-based (for example, what the user has, such as a magnetic card), acombination knowledge and token based (for example, like an ATMrequiring a card and a PIN), and biometric (for example, somethingunique to the user, like a fingerprint).

Due to technology proliferation, it has become increasingly easy toovercome existing authentication methods, which often rely on propertiesthat can be easily broken. Additionally, when authentication systemsrequire more user interaction, the more likely users will balk at theincrease in costs in time and money to the user. Authenticating users isbecoming more important as applications and services can no longer relyon authenticating the user using traditional methods alone.

This is a long-standing problem and a lot of work has been done in thisarea to date. However, no current solution is perfect and there is stilla need for new technology to be developed to help enterprisesauthenticate callers. For these reasons, there is a substantial need forimprovement in the response systems currently used in authentication ofusers and/or calling devices, without increasing the complexity and costto the users. In order to balance these interests, there is a long-feltneed in the art for authentication systems that are simpler and lessexpensive to implement and use, while providing improved authentication.

SUMMARY OF THE INVENTION

To this end, the disclosed systems and methods use active “pinging” inthe audio channel during the beginning of a phone call. The goal is tocharacterize the calling device and the network through which the callis passing through. The system sends a special sequence of tones (pings)from the receiver's end to the caller via the outgoing audio channel andlistens for any portion of that audio that gets returned through theincoming audio channel. The returned audio is then analyzed and comparedwith the sent audio, and that information is used to create a“PingerPrint” (i.e., a “fingerprint” unique to the calling device) ofthe calling device, and possibly the network as well, that can then bechecked against a stored, secure database on the enterprise (receiver's)system.

The system sends pings during the very early stage of the call and doesnot require user interaction. Some enterprise call response systemsactually pick up the call immediately, then play an artificial ring tonefor several seconds, letting the caller think that the call has not yetbeen picked up. During this time, the system queries commercialauthentication services, which determines if the call is likely to becoming from the calling number in the caller ID. Instead of playing astandard ring tone during this time, the pings are played, over adifferent ring tone (in some embodiments), or some other message to thecaller (in alternate embodiments). The returned portion of the pings arecollected at this time, and the information is processed before the callis transferred into the enterprise call response system. The system usesthe results to route the call properly.

One use case for the disclosed system and methods is that in which anenterprise has a group of registered users who call in to the systemrepeatedly, and there is a need to authenticate these callers to preventunauthorized access to the system. In this case, enrollment in thesystem may be required. This may preferably be done using a passiveenrollment method that does not require users calling in to the systemto explicitly take action to register or enroll in the system.Enrollment can be done automatically the first time a user calls in, andenrollment can also be updated automatically in the future if a userchanges his/her calling device or other changes are made. Passiveenrollment will help maintain a positive user experience, and this isimportance especially in commercial applications of the disclosedtechnology.

A challenge in authenticating the caller's device comes from the factthat the same enrolled caller may use different devices to call, such asa mobile phone versus a landline, for example. In addition, that samecaller may use different calling modes of the same device when calling.For example, a mobile phone user may call with the calling device inhand, held to his/her ear, or may use earbuds, or perhaps speakerphonemode. All of these different modes are likely to cause variations in theauthentication results. While this presents a challenge, this alsoprovides useful information. One planned approach for dealing withdifferent devices and modes for the same caller is to have multipleenrollments for the same caller. With passive enrollment, this likelywill not negatively impact the user experience of the caller.

In contrast to enrollment in to the system, the disclosed system andmethods may also be useful in cases in which no enrollment has takenplace, and this represents another use case. The technology can, andmost likely will, be used in conjunction with other voice securitytechnologies to build up a more robust security system. In this case,use of the system without enrollment can still play an important role,again because it collects new information that is not available throughany other voice security technology.

Many other objects, features, advantages, benefits, improvements andnon-obvious unique aspects of the disclosed embodiments, as well as theprior problems, obstacles, limitations and challenges that areaddressed, will be evident to the reader who is skilled in the art,particularly when this application is considered in light of the priorart. It is intended that such objects, features, advantages, benefits,improvements and non-obvious unique aspects are within the scope of thepresent invention, the scope of which is limited only by the claims ofthis and any related patent applications and any amendments thereto.

To the accomplishment of all the above, it should be recognized thatthis invention may be embodied in the forms illustrated in theaccompanying drawings, attention being called to the fact, however, thatthe drawings are illustrative only, and that changes may be made in thespecifics illustrated or described.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and itsembodiments, and the advantages thereof, reference is now made to thefollowing descriptions taken in conjunction with the accompanyingdrawings, in which:

FIG. 1A & FIG. 1B are schematic representations of embodiments of thedisclosed system.

FIG. 2 is a flow diagram depicting a method for authenticating a callwith enrollment in an enterprise system.

FIG. 3 is a flow diagram depicting a method for authenticating a callwithout enrollment in an enterprise system.

FIG. 4 depicts superimposed plots of both the outgoing and incomingaudio during a test call from a landline handset. Pings and returns arevisible as sharp vertical bars due to the compressed scale.

FIG. 5 depicts superimposed plots of both the outgoing and incomingaudio during a test call from a cell phone. Outgoing pings #1, #2 and #3are indicated by the label at the lower left.

FIG. 6 depicts a zoomed and magnified plot of Ping #2, and its returnfrom the landline test call. The return is received approximately 0.28sec. after the ping that caused it. This return has sharp rise andcutoff, like the ping, but its duration is significantly shorter thanthat of the ping.

FIG. 7 depicts a zoomed and magnified plot of Ping #2, and its returnfrom the cell phone test call. Now the return arrives approximately 0.76sec. after the ping. This return is broader, and of much lower amplitudethan that of the landline call.

FIG. 8 depicts the waveform of Ping #2.

FIG. 9 depicts the return from Ping #2 from the landline test call. Notethat the duration of this return is approximately one quarter that ofthe ping itself.

FIG. 10 depicts the return from Ping #2 from the cell phone test call.The duration of this return is much longer than that from the landline,while its amplitude is much less. It also has a notable envelope shape.Some other noise on the line is also visible before and after theenvelope.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following examples are included to demonstrate preferred andalternative embodiments. It should be appreciated by those of ordinaryskill in the art that the techniques disclosed in these examples arethought to represent techniques that function well in the practice ofvarious embodiments, and thus can be considered to constitute preferredmodes for their practice. However, in light of the present disclosure,those of ordinary skill in the art should appreciate that many changescan be made in the specific embodiments which are disclosed while stillobtaining a like or similar result without departing from the spirit andscope of the invention.

For purposes of these descriptions, a few wording simplifications shouldalso be understood as universal, except to the extent otherwiseclarified in a particular context either in the specification or in anyclaims. The use of the term “or” in the specification is used to mean“and/or” unless explicitly indicated to refer to alternatives only, orunless the alternatives are inherently mutually exclusive. Whenreferencing values, the term “about” is used to indicate an approximatevalue that includes the standard deviation of error for any particularembodiments that are disclosed or that are commonly used for determiningsuch value. “A” or “an” may mean one or more, unless clearly indicatedotherwise. Such “one or more” meanings are most especially intended whenreferences are made in conjunction with open-ended words such as“having,” “comprising,” or “including.”

In one embodiment 10 shown in FIG. 1, a calling device 110 (shown asmultiple calling devices 1-N) and a receiving entity 100 are shown. Thereceiving entity 100 is shown to include an enterprise call responsesystem 120 (“response system”), as well as call handling equipment 130.Call handling equipment 130 may include, but not be limited to, aPrivate Branch Exchange (PBX) system, a Session Border Controller (SBC),a Gigamon, a call audio recording system, an Interactive Voice Response(IVR) system, and any other call handling equipment that is capable ofreceiving and/or transferring calls as necessary according to thedisclosed methods for authentication of a calling device. Responsesystem 120 is shown to include an on-site computer system (with hardwareand software components) and a user interface that is adapted to enablea user to setup and control the response system 120, manage enrollments,and to deliver the results of the call authentication process.

The call handling equipment 130 is set up to receive incoming calls andis configured to forward the incoming call information to responsesystem 120. Response system 120 is configured to generate and send theping(s), and record the audio returns in real time. The response system120 takes the audio and processes the information in real time (usuallyas fast as possible during the call) in order to make a decision aboutthe authenticity of the caller as early in the call as possible, perhapseven before the call is taken into the Interactive Voice Response (IVR)system or by an agent. Response system 120 is preferably maintained in aserver, although this is not required.

Turning to FIG. 1B, there is shown another embodiment of the responsesystem 120 and related components. The main difference between theembodiment illustrated in FIG. 1A and the embodiment illustrated in FIG.1B is that some of the response system is cloud-hosted separately fromthe enterprise call center 100, as shown in FIG. 1B. For instance, theon-site computer system component of the response system 120 generatesthe pings and records the audio returns. In the cloud-hosted portion ofresponse system 120, there is a database, and the cloud-hosted portionprocesses and analyzed the recorded returns, provides a risk assessmentof the call being authenticated, and is configured to communicate any orall of this information to the on-site computer system.

In an alternate embodiment, when a call comes in to the response system120 it plays an audio WAV file which has been uploaded for use as anoutgoing “message” to the caller. The pings are incorporated into thisoutgoing message file. In some embodiments, the pings are generated inreal time by the incoming call routing system. All incoming and outgoingaudio during the call can be recorded as a TCP dump. The captured datais then analyzed offline and observations from the analysis are used tomodify the design of the outgoing pings with the goal of optimizing therobustness, and value for authentication of the method.

In some embodiments, the response system 120 creates and selects theoptimal ping tones by first creating various outgoing audio files with aseries of different types of ping tones. These may includesingle-frequency bursts with different time envelopes, upward ordownward chirps of various durations, either linear or logarithmic,bursts of more complex waveforms of different durations and timeenvelope shapes, etc. These different types of pings are designed toprovide informative test results that will lead to optimization of thepings to be used in a product implementation.

Echo cancelling technology is now ubiquitous (or nearly so) in telephonenetworks and can affect the ping results. In some embodiments theresponse system 120 turns off echo cancellation for a particular call byplaying one or more special tones on the line at the outset of the call.The tones are those used by fax machines and dialup modems. They arecalled the “ANS” and “CNG” tones. As is known in the art the ANS tone isthe critical one to play in order to affect echo cancelation, so in someembodiments the outgoing audio ping files include an ANS tone that isplayed at the very beginning. This ANS tone is spec'd at 2100 Hz, withphase shifts of 180 degrees every 450 milliseconds (ms). Playing thisANS tone has a very definite effect on the pings that get returned, andin general, it improves the strength and number of the returned pings,as expected under the assumption that it has disabled echo cancelation.In some embodiments, the response system 120 determines in tests withthe ANS tone whether or not echo cancellation is actually being turnedoff and optimizes the ping tone to maximize quality. In someembodiments, the response system 120 uses ping envelop shapes that canget past any echo cancelation in the network.

A wide range of different ping tones has been tested and the range ofuseful tones is being narrowed down. In some embodiments, the responsesystem 120 will test which pings work the best during a period ofinitialization (“initialization phase”). In one embodiment 10, risingchirps work much better than falling chirps. Most of the test tones havebeen bursts of varying lengths ranging between 5 ms and 150 ms, withfrequencies of between 60 Hz and 4 kHz. The max frequency of 4 kHz waschosen because the sample rate used in the phone network is 8 kHz,however it quickly became clear that the 4 kHz tones were not gettingthrough well at all, so now a frequency ceiling of 2 kHz is typicallyobserved.

The goal of the initialization phase and the testing is to create“fingerprints” or “characterization” of a calling device 110, includingthe network, to provide useful information as part of the responsesystem 120 that can authenticate a caller. Using the active probing bymeans of audio pings, the response system 120 creates this “FingerPrint”by numerical analysis of the returns from the pings, and how theycompare with what was sent out.

There are at least two embodiments of this characterization. Oneembodiment 20 involves authenticating enrolled users. This requirescallers to be enrolled into an enterprise system, such as a bank'scustomer databases. Enrollment with this technology is totally passive,which is important for a positive user experience. The caller does nothave to actively do anything to enroll. The enrollment happensautomatically when new users call in. The response system 120automatically updates the enrollment information when a user changeshis/her device, moves to a new location or telephone system, or thephone network changes. The response system 120 compiles and maintainsmultiple enrollment PingerPrints for each user to cover multiple devices(such as a cell, landline, office phone, etc.). Multiple enrollments mayalso be required to cover the use of earbuds or speakerphone mode, whichcan change the ping returns. When an enrolled caller calls in again, theresponse system 120 authenticates his/her device by comparing thereturned data with that stored in the response system 120's database bymatching and validating the device type or network against serviceprovider records.

Turning to FIG. 2, there is shown a flow diagram of an authenticationprocess with enrollment 20. In step 200, a calling device 110 places acall to a receiving entity's system, referred to as an enterprise callresponse system (“response system 120”). In the next step, the responsesystem will either pick up the call (201), temporarily suspend the call(202), or play audio pings with (or without) a fake ring tone or otheroutgoing message (203). If the response system plays audio pings (203),in the next step 204 the calling device 110 receives pings via the audiochannel and some portion of the pings is passively reflected orretransmitted by the calling device 110 with distortion and/or a delay.In other words, nothing has to be done to or with calling device 110 inorder for the portion of the pings to be reflected or retransmitted tothe response system 120. The user of calling device 110 does not need toperform any affirmative step, and no special application or hardwareneeds to be added or installed on the calling device 110 in order forthe portion of the pings to be reflected or retransmitted to theresponse system 120. The portion of the pings that is reflected orretransmitted by the calling device 110 with distortion and/or a delayis called “returns.” In step 205, the response system receives thereturns via the audio channel. In step 206, the response system records,analyzes, and stores the returns with other metadata such as the callingnumber, in order to create a “PingerPrint” of the calling device 110.

In step 207, the response system attempts to match the PingerPrint withexisting local database entries previously enrolled by the responsesystem. If the response system finds a match (208), in step 209 theresponse system routes the call according to user-customizable settingsas a valid caller. If the response system does not find a match (210),the response system determines if the calling device 110 is a first timecaller (211). If it is a first time caller (212), in step 213 theresponse system stores the PingerPrint as a new enrollment. Storage ofthe new enrollment may be accomplished automatically by response system120 once it is determined that the PingerPrint does not match anypre-existing database entries. Alternatively, storage of the newPingerPrint as a new enrollment may require intervention from acall-taking agent in order to complete the storage process. If it is nota first time caller (214), in step 215 the response system routes thecall according to user-customizable settings. Then, one of two possiblesteps will occur. In step 216, the response system confirms the calleras valid by an alternate method, and the new PingerPrint information isadded to the existing enrollment database for that caller. In thealternative step 217, the response system blocks the call, or the “bad”caller is handled in some other way. For example, an organizationemploying response system 120, upon determination that a call is a “bad”call, rather than blocking the call might reroute that call to a specialcall-taking agent, the organizations fraud department, to voicemail, orsome other special IVR system. One important reason to send such a callto a special live agent is to have a human determine if the caller istruly a bad actor, or if the Automated Audio Call ID system incorrectlylabeled the caller as bad. This information can then be used to improvethe performance of the Automated Audio Call ID system. Another reason toroute the call elsewhere is to collect information on malicious callers.

Another embodiment 30 of the “characterization” requires access tocarrier records of caller's information. No enrollment is needed withthis embodiment. In this embodiment 30, a large database of device andnetwork responses to the pings is stored in a central location. Thisdoes not necessarily need to be on enterprise's premises. This databasecan be housed in the cloud, or locally at a secure location that can beaccessed by all enterprise customers who want to use the response system120. This requires the database to be built up over time by collectingping data from a wide variety of devices and networks. When a call comesinto the response system 120, all information received from the carrier(such as AT&T, Verizon, etc.), plus the ping data is sent to the centrallocation. The enterprise using the response system 120 receives the calland call information and sends an authentication query to the centrallocation. The central location manages queries, processes data, andsends the results back to the enterprise. The returned result of theauthentication query may simply be a whether or not the phone number ofthe caller matches the type of device registered with that number.

Turning to FIG. 3, there is shown a flow diagram of an authenticationprocess without enrollment 30. In step 300, a calling device 110 placesa call to a response system. In the next step, the response system willeither pick up the call (301), temporarily suspend the call (302), orplay audio pings with (or without) a fake ring tone or other outgoingmessage (303). If the response system plays audio pings (303), the nextstep 304 is the calling device 110 receives pings via the audio channeland some portion of the pings are reflected or retransmitted by thecalling device 110 with distortion and/or a delay. The portion of thepings that are reflected or retransmitted is called “returns.” In step305, the response system receives the returns via the audio channel. Instep 306, the response system records, analyzes, and stores the returnswith other metadata such as the calling number, in order to create a“PingerPrint” of the calling device 110. In step 307, parameters of thePingerPrint are compared with information in the global databasepreviously stored by all users of the response system 120. This step 307can be completed locally at the response system or on the globaldatabase server. If the PingerPrint matches information from thedatabase (308), in the next step 309 the call is flagged as “GOOD,” andthe response system routes the call according to user-customizablesettings as a likely valid caller (may also show passing score). If thePingerPrint does not match information from the database (310), in thenext step 311 the call is flagged as “BAD”, and the response systemroutes the call according to user-customizable settings as a likelymalicious caller (may also show failing score). The informationregarding whether a call is “GOOD” or “BAD” is defined here as“results.” After the call is flagged as “GOOD” or “BAD”, in the nextstep 312 the response system uploads the results, all PingerPrintparameters and metadata to the global database. In the next step 313,the response system and/or the global database updates the pass/failcriteria based on the new data to improve reliability.

Both of these embodiments require much the same technology, and dataanalysis, but they are different in terms of business case, and who ownsand maintains the data. Prior to analyzing the data, some pre-processingmay be required. This can include things like scaling the waveform tomake its amplitude larger, or to match other waveforms; filtering of thesignal to remove noise, or unwanted features; truncating part of thesignal to remove superfluous audio; dicing up the signal into separatepings before processing; and more. After pre-processing, bothtime-domain and frequency-domain analysis of the signals is used toproduce the PingerPrint of the calling device 110. This takes the formof a numerical score of sorts, that can be easily compared with that ofa new call to determine if the new call is likely to be coming from thesame device as that of a previously registered caller.

Time-domain analysis looks at the time delay between the ping and itsreturn, the shape of the time envelope of the return, jitter, or anyvariation in the time between pings and returns, etc. Frequency-domainanalysis uses Fourier analysis to examine how the frequency spectrum(including phase) of the return may differ from the outgoing ping, andhow it may differ from returns from other devices. Both of these generalmethods of analysis are powerful, and have pros and cons, as determinedat time of implementation of the response system 120.

The response system 120 uses an algorithm or algorithm suite to processthe data and create a PingerPrint of each calling device 110. Two veryimportant and related considerations in designing the processing anddata analysis algorithms are speed and computational cost. Both need tobe minimized in order to create a positive user experience for callers,and a viable product for enterprises that will not be cost prohibitiveor limit their call flow. This is one reason why both time and frequencydomain analysis methods are evaluated and possibly used together as makesense in the particular implementation. Other analysis methods may alsobe used, such as some form of statistical analysis.

Another embodiment involves randomizing the pings by changing the orderin which they are delivered, or varying the timing, and time spacingbetween them. This is important in the event that would be hackersfigure out how the response system 120 works and try to spoof it bysending out artificial ping returns. Randomizing the pings can helpthwart such hacking attempts. In addition, the “active” or useful pingsmay also be camouflaged with “inactive” pings or other sounds, making iteven more difficult for hackers to work out how the response system 120is working, and what they might try to hack in.

FIGS. 4 and 5 are superimposed plots of both the outgoing and incomingaudio from one such pair of test calls used during the initializationphase of the implementation of the invention onto a new enterprisecalling system. FIG. 4 is for a call from the landline handset, and FIG.5 is for a cell phone call. The outgoing signal is in blue, and theincoming signal is in red in each of the plots. These plots show thefull record, so the waveforms are compressed horizontally since therecords are long, but they show the number, relative amplitudes, timegaps and durations of the outgoing and incoming pings. The ANS tone isalso seen at the beginning of the call in the outgoing signal, and thereare even some returns from the ANS tone in the incoming audio from thelandline handset, most likely from the sharp, discontinuous phase shiftsin the ANS tone every 450 ms.

Focusing on the second ping (Ping #2) in this test, and its return,FIGS. 6 and 7 show zoomed-in plots of a 1.5 second (approx.) long windowcentered between the outgoing ping (in blue) and the return from thatping (in red) for the landline and cell phone test calls respectively.The second ping, shown in these plots is an 80 ms long burst at 500 Hzwith a very sharp onset, and cutoff. This is why this ping appears as arectangular blue block in the plots above. The plots are greatlymagnified as well, so peaks are cut off in the vertical axis. Theseplots show clearly some important differences in the return from thelandline versus the cell phone with identical outgoing pings. There is adelay in the return from the landline after receiving the ping ofapproximately 0.28 seconds, while the return from the cell phone arrivesapproximately 0.76 seconds after receiving the same ping. Also, it canbe clearly seen that the amplitude, duration and time envelope of thereturns are also very different between the landline and cell phone. Thelandline return amplitude from this particular ping is much greater thanthat from the cell phone, but it is also shorter, and more square in itsenvelope shape. Despite the low amplitude of the returns, even the weakreturns from the cell phone are still quite audible, and also visible inthe plots.

To clarify the differences between the two returns and help inunderstanding how this information may be used to characterize thecalling device 110, FIGS. 8, 9, and 10 show the outgoing ping #2waveform, the waveforms of the landline return and cell phone returnfrom ping #2, respectively. Each of these plots shows a segment of theaudio waveform that is 100 ms long and centered on the ping or return.The vertical axes are scaled for each differently so the waveform andtime envelope of each is clearly visible in the plots.

The differences in the response from the landline handset, and the cellphone, with all other test parameters held constant, is very clear.Repeated calls from the same landline and cell phone produced verysimilar results, indicating that the characteristics of the returns arerelated to some combination of the calling device 110, and the network.

The response system 120 starts the initialization phase with relativelysimple waveforms and time envelopes tested for the pings. These are veryuseful in beginning to understand what might work best to probe thecalling device 110 in this way. Generally, relatively low frequenciesproduce more consistent, and stronger returns, however, this may bemisleading since it could also have to do with the shape of the timeenvelope of the ping waveform.

After testing pings with simple waveforms, the response system 120performs testing with a series of new ping waveforms. These includesimpler waveforms at some new frequencies, as well as much more complexwaveforms, some of which are a mix of longer, slower-rising envelopes atone frequency with sharp-rising, shorter packets at a differentfrequency. Tests with more complex waveforms are run, for examplewaveforms that change their frequency spectrum during their timeenvelope. These may include pulse waves with a time-varying duty cycleor saw-tooth wave with time-varying frequency. The response system 120performs the tests to develop pings that produce good returns withoutthe need to pre-condition the line with the ANS tone.

Although the present disclosure has been described in terms of theforegoing disclosed embodiments, this description has been provided byway of explanation only and is not intended to be construed as alimitation of the invention. Even though the foregoing descriptionsrefer to embodiments that are presently contemplated, those of ordinaryskill in the art will recognize many possible alternatives that have notbeen expressly referenced or even suggested here. While the foregoingwritten descriptions should enable one of ordinary skill in thepertinent arts to make and use what are presently considered the bestmodes of the invention, those of ordinary skill will also understand andappreciate the existence of numerous variations, combinations, andequivalents of the various aspects of the specific embodiments, methods,and examples referenced herein.

Hence the drawing and detailed descriptions herein should be consideredillustrative, not exhaustive. They do not limit the invention to theparticular forms and examples disclosed. To the contrary, the inventionincludes many further modifications, changes, rearrangements,substitutions, alternatives, design choices, and embodiments apparent tothose of ordinary skill in the art, without departing from the spiritand scope of this invention, as defined by any claims included herewithor later added or amended in an application claiming priority to thispresent filing.

Accordingly, in all respects, it should be understood that the drawingsand detailed descriptions herein are to be regarded in an illustrativerather than a restrictive manner and are not intended to limit theinvention to the particular forms and examples disclosed. Rather, theinvention includes all embodiments and methods within the spirit andscope of the invention as claimed, as the claims may be amended,replaced or otherwise modified during the course of related prosecution.Any current, amended, or added claims should be interpreted to embraceall further modifications, changes, rearrangements, substitutions,alternatives, design choices, and embodiments that may be evident tothose of skill in the art, whether now known or later discovered. In anycase, all substantially equivalent systems, articles, and methods shouldbe considered within the scope of the invention and, absent expressindication otherwise, all structural or functional equivalents areanticipated to remain within the spirit and scope of the presentlydisclosed systems and methods. The invention covers all embodimentswithin the spirit and scope of such claims, irrespective of whether suchembodiments have been remotely referenced here or whether all featuresof such embodiments are known at the time of this filing.

We claim:
 1. A method for authenticating calls with enrollment, themethod comprising: a) providing a response system, wherein the responsesystem is hosted on a server, and wherein the response system is inelectronic communication with a database; b) receiving, by the responsesystem, a call from a calling device; c) generating audio pings, whereinthe audio pings are incorporated into an outgoing message; d)transmitting the outgoing message incorporating the audio pings from theresponse system to the calling device through an audio channel; e)reflecting at least a portion of the transmitted audio pings from thecalling device back to the response system; f) receiving, at theresponse system, the at least a portion of the retransmitted audio pingsthrough the audio channel; g) recording, analyzing, and storing, by theresponse system, the at least a portion of the retransmitted audio pingsalong with other metadata to create a PingerPrint of the calling device;h) determining, by the response system, whether the PingerPrint of thecalling device matches any existing database entries by comparing thePingerPrint with existing database entries previously stored in thedatabase; and i) after determining whether the PingerPrint of thecalling device matches a database entry previously stored in thedatabase, routing the call according to user-customizable settings. 2.The method of claim 1, further comprising enrollment, wherein theresponse system, upon comparing the PingerPrint with existing databaseentries, determines that the PingerPrint of the calling device does notmatch any database entries and the call from the calling device isdetermined to be a first-time caller, then automatically storing thePingerPrint of the calling device in the database as a new enrollment.3. The method of claim 1, further comprising enrollment updating,wherein the response system, upon comparing the PingerPrint withexisting database entries, determines that the PingerPrint of thecalling device does not match any database entries and the call from thecalling device is determined to not be a first-time caller, then addingthe PingerPrint of the calling device to the existing database entries.4. The method of claim 1, wherein the comparison of the PingerPrint ofthe calling device with existing database entries is performed locallyby the response system.
 5. The method of claim 1, wherein the comparisonof the PingerPrint of the calling device with existing database entriesis performed on a global database server.
 6. The method of claim 1,wherein a portion of the response system is cloud-hosted on a server. 7.The method of claim 1, wherein the at least a portion of the transmittedaudio pings reflected back to the response system further comprisesdistortion and/or delay.
 8. A system for authenticating calls, thesystem comprising: a) a response system hosted on a server, wherein theresponse system is in electronic communication with a database; and b) acalling device configured for placing a call; c) wherein the responsesystem is configured to perform a method of authenticating the callingdevice, the steps of the method comprising: 1) receiving, by theresponse system, a call from a calling device; 2) generating audiopings, wherein the audio pings are incorporated into an outgoingmessage; 3) transmitting the outgoing message incorporating the audiopings from the response system to the calling device through an audiochannel; 4) reflecting at least a portion of the transmitted audio pingsfrom the calling device back to the response system; 5) recording,analyzing, and storing, by the response system, the at least a portionof the retransmitted audio pings along with other metadata to create aPingerPrint of the calling device; 6) determining, by the responsesystem, whether the PingerPrint of the calling device matches anyexisting database entries by comparing the PingerPrint with existingdatabase entries previously stored in the database; and 7) afterdetermining whether the PingerPrint of the calling device matches adatabase entry previously stored in the database, routing the callaccording to user-customizable settings.
 9. The system of claim 8,wherein the response system, upon comparing the PingerPrint withexisting database entries, determines that the PingerPrint of thecalling device does not match any database entries and the call from thecalling device is determined to not be a first-time caller, then addingthe PingerPrint of the calling device to the existing database entries.10. The system of claim 8, wherein the response system, upon comparingthe PingerPrint with existing database entries, determines that thePingerPrint of the calling device does not match any database entriesand the call from the calling device is determined to not be afirst-time caller, then adding the PingerPrint of the calling device tothe existing database entries.
 11. The system of claim 8, wherein thecomparison of the PingerPrint of the calling device with existingdatabase entries is performed locally by the response system.
 12. Thesystem of claim 8, wherein the comparison of the PingerPrint of thecalling device with existing database entries is performed on a globaldatabase server.
 13. The system of claim 8, wherein a portion of theresponse system is cloud-hosted on a server.
 14. The system of claim 8,wherein the at least a portion of the transmitted audio pings reflectedback to the response system further comprises distortion and/or delay.